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EFI fuel pump, a quieter one
Craigorypeck - 15/1/12 at 09:25 PM

I have a blue 038 3 bar 135 L/Hr pump, its so loud you can hear it at idle, thats with a single box exhaust and supercharger going too.. Q is do any of you have experience with a quiet(er) pump?
Thanks


austin man - 15/1/12 at 09:48 PM

have you mounted it direct to the chasis if so consider mounting it on rubber bobbins a lot of the noise travels through the chasis


Craigorypeck - 15/1/12 at 10:28 PM

its held on with clamps that have rubber in between the clamp and pump casing


MikeRJ - 16/1/12 at 12:07 AM

quote:
Originally posted by Craigorypeck
its held on with clamps that have rubber in between the clamp and pump casing


That's not really enough. On production cars these pumps were mounted on soft rubber "cotton reel" type mounts.

Any external pump is going to be relatively noisy in a Locost (compared to a production car) though.


Craigorypeck - 16/1/12 at 12:17 AM

I was thinking that since i posted the reply, I ordered some 6mm thick closed cell foam sheets on ebay, gonna role the pump up in that twice, should work? how hot do pumps get tho..? I might just wrap where the clamps are if it was gonna cause a prob...?


jimgiblett - 16/1/12 at 10:23 AM

My experience of Bosch pumps it that they get hot if enclosed (too hot to touch) . But they also get much noisier when they get hot.

- Jim


loggyboy - 16/1/12 at 10:33 AM

These would help:
http://www.cbsonline.co.uk/product/Cotton_Reel_Rubber_Mount_20mm_Dia_x_15mm_COT1


rachaeljf - 16/1/12 at 12:53 PM

They are supposed to be cooled by the fuel running through them so it shouldn't be a problem wrapping them, although I have never completely wrapped a pump to insulate the sound. "Too hot to touch" is around 60 degrees C, which isn't really that hot for most machines, so touch temperature is not a good indicator unless you know that normally you would be able to touch the offending item.

Other things to check:
If the inlet is in any way restricted the pump will get noisy.
Liquids transfer sound quite well, so the "buzz" can emanate from any rigid fuel pipe near the pump that touches the chassis.

Cheers R

[Edited on 16/1/12 by rachaeljf]


jimgiblett - 16/1/12 at 02:25 PM

quote:
Originally posted by rachaeljf
They are supposed to be cooled by the fuel running through them so it shouldn't be a problem wrapping them, although I have never completely wrapped a pump to insulate the sound. "Too hot to touch" is around 60 degrees C, which isn't really that hot for most machines, so touch temperature is not a good indicator unless you know that normally you would be able to touch the offending item.

[Edited on 16/1/12 by rachaeljf]


My comment was more about the increased noise (which the OP was commenting on) that bosch pumps emit when they get warm. Wrapping it up more than just to reduce vibration may be counter productive if it makes the pump run hotter.

Also where is it located (I have seen fuel pumps in hot engine bays)?

If you can get it behind the driver (possibly under the tank in cool airflow then it should reduce noise (or at least make it less audible to the driver and passenger when driving along).

- Jim


blakep82 - 16/1/12 at 02:35 PM

i used these
eBay Item

i've got a facet pump, but i guess yours can mount with something similar?

[Edited on 16/1/12 by blakep82]


rachaeljf - 16/1/12 at 02:40 PM

Fair enough I agree with you Jim, I have never considered completely wrapping a pump to quieten it. They are supposed to be fuel cooled, but I would prefer not to invite disaster!

One should look at where car makers put their external pumps - out the back away from passengers, close to the tank to minimise suction head too. All helps to keep the pump and people happy and quiet.

[Edited on 16/1/12 by rachaeljf]


Craigorypeck - 16/1/12 at 05:25 PM

Its in the engine bay, low down on the chassis rail,

I've seen these -

http://www.merlinmotorsport.co.uk/p14899/SOUND-SLEEVE-FOR-WALBRO-&-SYTEC-PUMPS-&-INJECTION-FILTERS/product_info.html

They incase the entire pump so maybe it will be ok?

I have 2 clamps like these,
eBay - The UK's Online Marketplace
with the tension bolt removed and replaced with a far longer threaded bar which goes through the chassis rail.
I'll just wrap the pump in the 2 places directly under the clamps, bit of adhesive to hold rubber foam in place, only 1/3 of pump will be covered..

If its still being a bollock I'll make up something that uses the bobbins. pump has no mounting flanges btw.

Thanks!


BaileyPerformance - 16/1/12 at 05:37 PM

quote:
Originally posted by Craigorypeck
I have a blue 038 3 bar 135 L/Hr pump, its so loud you can hear it at idle, thats with a single box exhaust and supercharger going too.. Q is do any of you have experience with a quiet(er) pump?
Thanks


Hello,

What size is the feed pipe to the pump from the tank? - could be cavitating - does it get warm?
Are you sure its a Bosch pump not a Chinese copy?


Craigorypeck - 16/1/12 at 05:59 PM

Its 8mm id pipe from tank to pump.

I haven't checked if it gets warm.. yet

Could be a chinese job tbh

here tis- http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=370361374745&ssPageName=ADME:L:OC:GB:1123


rachaeljf - 16/1/12 at 06:34 PM

Hmmm, that's a bit small I reckon. Should be 12 mm in and 8 mm out. That coupled with the extra pipe run from the tank you are strangling the poor thing!


Craigorypeck - 16/1/12 at 07:02 PM

the pumps is as low as the bottom of the tank so will be gravity fed too to some extent.

My drawing board gets re-visited way too often!!!

Any suggestions to a pump that would handle the current location?


rachaeljf - 16/1/12 at 07:04 PM

You might be ok just making the feed pipe 12 mm. How far is it actually from the tank?

[Edited on 16/1/12 by rachaeljf]


Craigorypeck - 16/1/12 at 07:11 PM

approx 3 metres from sender to pump..


rachaeljf - 16/1/12 at 07:15 PM

But it's all at low level? Try going to 12 mm pipe as your first go, might be ok.


Craigorypeck - 16/1/12 at 07:23 PM

yes, near horizontal to the base of tank


rachaeljf - 16/1/12 at 07:31 PM

Yep, I suggest you try 12 mm hose, that might be enough to let your pump run properly.

Cheers R


BaileyPerformance - 17/1/12 at 12:01 PM

quote:
Originally posted by rachaeljf
Hmmm, that's a bit small I reckon. Should be 12 mm in and 8 mm out. That coupled with the extra pipe run from the tank you are strangling the poor thing!


Agreed!

You must use 12mm or bigger pipe to feed the pump, and keep the feed pipe as short as poss.